In the centennial of Ettore Majorana’s birth (1906–1938?), we re-examine some aspects of his fundamental scientific production in atomic and molecular physics, including a not well known short communication. There, Majorana critically discusses Fermi’s solution of the celebrated Thomas–Fermi equation for electron screening in atoms and positive ions. We argue that some of Majorana’s seminal contributions in molecular physics already prelude to the idea of exchange interactions (or Heisenberg–Majorana forces) in his later works on theoretical nuclear physics. In all his (...) papers, he tended to emphasize the symmetries at the basis of a physical problem, as well as the limitations, rather than the advantages, of the approximations of the method employed. (shrink)

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We review the early works which were precursors of the Conceptual Density Functional Theory. Starting from Thomas–Fermi approximation and from the exact formulation of Density Functional Theory by Hohenberg and Kohn’s theorem, we will introduce electronegativity and the theory of hard and soft acids and bases. We will also present a general introduction to the Fukui functions, and their relation with nucleophilicity and electrophilicity, with an emphasis towards the importance of these concepts for chemical reactivity.

Bilimin ne olduğunun belirlenmesi ve bu bağlamda bilimin sözde bilim ya da bilimsel olmayan alanlara ilişkin sınırının nasıl çizileceği tartışması, bilim felsefesinde sınır çizme problemi olarak ele alınmaktadır. Çalışmanın ana konusunu oluşturan bu problem, özellikle yirminci yüzyıldan itibaren, bilim felsefecileri tarafından birçok ölçüt ortaya konularak çözümlenmeye çalışılmıştır. Bu ölçütler genellikle, bilim ile sözde bilim arasındaki sınırı belirlemek amacıyla, bilimi mantık ve mantıksal önermeler üzerinden değerlendirmektedir. Şu ana kadar Viyana Çevresi, Popper, Kuhn, Lakatos gibi filozoflarca ortaya konulan ölçütler, nihai olarak problemi (...) mantıksal açıdan ele almıştır. Sınır çizme sorununun mantıksal açıdan ya da mantıksal ifadeler aracılığıyla ele alınması demek; sorunu içeriği yerine daha çok biçimsel açıdan ele almak anlamına gelmektedir. Ayrıca, ifade, kuram, araştırma programı gibi bilim öğelerinin bilimsellik durumunu tespit edebilmek amacıyla önerilen ölçütün, tek tek gerekli ve hep birlikte yeterli olan uygun sınır çizme ölçütünü karşılaması anlamına da gelmektedir. Bu çalışma, gerek ve yeter koşul arayışının, bilimin değişken ve çeşitli yapısını tam olarak yakalayamayacağını ve bilimin belirlenmesinin ve sınırının çizilmesinin bu yöntemle mümkün olmayacağını vurgulamaktadır. Bu konunun mutlaka sosyolojik açıdan da ele alınması gerekmektedir. Bilimin sosyal yapısına, değerler sistemine de bakmamız gerekir. Sonuç olarak, sınır çizme probleminin gerek ve yeter koşulun ortaya koyduğu katı ve ortak özellikler üzerinden sonuçlandırılamayacağı, bunun yerine bilimin “aile benzerliği yaklaşımı” çerçevesinde ele alınması gerektiği vurgulanacaktır. Aile benzerliği yaklaşımının temel oluşturduğu çok boyutlu ölçüt, bu sorunun çözümünde sosyal etkenleri dâhil etmesi, bilimin çeşitliliğini kapsayabilecek ölçüde çoklu ve esnek yapıda olması ile katkıda bulunacaktır. (shrink)

Objectives: To report the attitudes and opinions of subjects in US clinical trials about whether or not, and why, they should receive post-trial access (PTA) to the trial drug, care and information. Design: Focus groups, short self-administered questionnaires. Setting: Boston, Dallas, Detroit, Oklahoma City. Participants: Current and recent subjects in clinical trials, primarily for chronic diseases. Results: 93 individuals participated in 10 focus groups. Many thought researchers, sponsors, health insurers and others share obligations to facilitate PTA to the trial drug, (...) if it benefited the subject, or to a therapeutic equivalent. Some thought PTA obligations include providing transition care (referrals to non-trial physicians or other trials, limited follow-up, short-term drug supply) or care for long-term adverse events. Others held, in contrast, that there are no PTA obligations regarding drugs or care. However, there was agreement that former subjects should receive information (drug name, dosage received, market approval date, long-term adverse effects, trial results). Participants frequently appealed to health need, cost, relationships, reciprocity, free choice and sponsor self-interest to support their views. Many of their reasons overlapped with those commonly discussed by bioethicists. Conclusion: Many participants in US trials for chronic conditions thought there are obligations to facilitate PTA to the trial drug at a “fair” price; these views were less demanding than those of non-US subjects in other studies. However, our participants’ views about informational obligations were broader than those of other subjects and many bioethicists. Our results suggest that the PTA debate should expand beyond the trial drug and aggregate results. (shrink)

We apply the distinction between parameter independence and outcome independence to the linear and nonlinear models of a recent nonrelativistic theory of continuous state vector reduction. We show that in the nonlinear model there is a set of realizations of the stochastic process that drives the state vector reduction for which parameter independence is violated for parallel spin components in the EPR-Bohm setup. Such a set has an appreciable probability of occurrence (≈ 1/2). On the other hand, the linear model (...) exhibits only extremely small parameter dependence effects. We investigate some specific features of the models and we recall that, as has been pointed out recently, if one wants to be able to speak of definite outcomes (or equivalently of possessed objective elements of reality) at finite times, one has to slightly change the criteria for their attribution to physical systems. The concluding section is devoted to a detailed discussion of the difficulties which one meets when one tries to take, as a starting point for the formulation of a relativistic theory, a nonrelativistic scheme which exhibits parameter dependence. Here we derive a theorem which identifies the precise sense in which the occurrence of parameter dependence forbids a genuinely relativistic generalization. Finally we show how the appreciable parameter dependence of the nonlinear model gives rise to problems with relativity, while the extremely weak parameter dependence of the linear model does not give rise to any difficulty, provided one takes into account the appropriate criteria for the attribution of definite outcomes. (shrink)

Bu yazı rüyasız uykuyu bilincin çeperinde kalan bir fenomen, Edmund Husserl’in deyimiyle deneyimin bir sınır-durumu (Limesfall) olarak ele almaktadır. Fenomenolojik açıdan, rüyasız uyku bize gündelik hayatımıza şekil veren olağan deneyimlere özgü uyanık bilinçliliğin ardına geçmeyi dayatır. Uyurken bilinç asla ortadan kalkmaz. Dolayısıyla ölümden farksız ve bilinçten tamamen yoksun mutlak bir uyku teorik bir kurgudan ibarettir. Yazının birinci bölümünde felsefe tarihi boyunca rüyasız uyku hakkında görüş ileri süren filozoflar üzerinde durulmaktadır. Immanuel Kant’ın tam aksine John Locke rüyasız bir uykuya imkân tanır. (...) Fakat rüyasız uykuyu bilinçsiz bir zihin hali olarak kabul eden Locke’dan farklı olarak felsefede uyuyan zihne bir duyarlık atfeden René Descartes, G.W. Leibniz ve (başlı başına üçüncü bölümü kendisine ayırdığımız) Husserl gibi filozoflar bilincin uykuda hiçbir zaman tamamen ortadan kalkmayacağı tezini destekler. Ne var ki uykudaki zayıf bilinçliliği göz önünde bulundurmayı önleyen engellerin başında bilinci refleksiyonun bir başarısı olarak görmek gelir. Bilinci refleksiyona eşitleyen her yaklaşım uyurken tamamen bilinçsiz olduğumuz inancını destekleyecektir. Bunun sebebi uykuda refleksiyonun mevcut olmamasıdır. Oysa sadece uyanıkken mümkün olan refleksiyon faaliyeti ortadan kalktığında bile bulanık, edilgin ve cılız bir arka plan bilinci varlığına devam eder. Dahası, uyurken uyanabilmenin yegâne koşulu böylesi bir bulanık bilince zaten sahip olmamızdır. Uyanabilmek için bizi dışarıdan etkileyenin öne çıkıp bir fark yaratacak biçimde bilincinde olmak gerekir. (shrink)

A well-documented defense of the thesis that St. Augustine held the city of man, especially Rome, to contain many relative goods, however evil it was from the absolute standpoint of goodness consisting in the worship of the true God. O'Meara discusses in some detail many contemporary critics, e.g., Ernest Barker, who oppose this interpretation, and argues on the basis of historical circumstance and Augustine's own declarations in works other than the City of God.--R. C. N.

That mankind's evolution is through genetics and cultural acquisition together, but not through either alone, is the thesis of these interesting Silliman lectures. Dobzhansky examines evolutionary theories from Darwinism to Social Darwinism to show the extent to which genetic inheritance requires certain environmental conditions, and vice versa, for mankind to evolve as it has. He also traces the origin of culture relative to man's genetic make-up, and considers the future impact of civilization, e.g., population expansion, the control of disease instead (...) of the genetic death of those susceptible, etc. The book is well documented and offers an excellent assessment of scientific findings; on the philosophic side, Dobzhansky approves as "a ray of hope," though "patently undemonstrable by scientifically established facts," Teilhard de Chardin's thesis that evolution is going toward "a harmonized collectivity of consciousnesses, equivalent to a kind of superconsciousness."--R. C. N. (shrink)

Analyses of the height variation of 16-year-old members of the British National Child Development Study revealed a number of biological and social variables which associated with stature. After multiple regression analyses only eight variables, namely social class, family size, tenure , crowding status, number of children sleeping in the bed, region of the country, sex of child, and pubic hair rating, remained significant. The total variation explained by these biosocial variables was 37·5%.

Having known classical wave optics and wave mechanics, can we reverse Schrödinger's path and extend the concept of families of rays of light to provide a new exact rendering of quantum optics including the Bose nature of photons? This question is answered in the affirmative, and the implications of the Bose symmetry for certain nonlocal correlations of the many-ray distribution functions are worked out. The similarities and the differences between classical and quantum wave optics are brought out. The ray-ray Bose (...) correlation is analyzed. The generating functional for the many-ray distribution functions is formulated; and the notion of paraxial illumination for quantum optics is made precise. (shrink)

Data taken by the Mark II detector at the PEP storage ring was used to measure the rate of dilepton production in multihadronic events produced by e+e- annihilation at √s=29 GeV. We determine the probability that a hadron initially containing a b quark decays to a positive lepton to be 0.17-0.08+0.15, with 90% confidence level limits of 0.06 and 0.38. © 1990.

Cultural taboos and their sanctionshave helped to check abuse of the environmentat least among the local people. The disregardfor these traditional checks and balancesespecially among Christians has adverselyaffected their enforcement at this time. Theenvironment and culture preservation inAwka-South were investigated. The faithfulobservance of the traditional laws in the studyarea was attributed to the fact that Awka-Southarea had remained occupied by the same peoplefor centuries. The study showed that thepreserved forests and their shrines in Nibotown have largely remained intact. In Nisetown, (...) however, with nine shrines still inexistence, the rules have relaxed a little,mainly because they embraced modernization. Inthis town, the fringes of the forests may beused for farming but no felling of trees wouldbe allowed. The ``god'' of the shrine in Obunaguvillage was much revered until the advent ofChristianity. This religion has had an erodingeffect on the taboos, which were put in placeto protect their forests and streams. Theabandonment of traditional cultural practicesis doing harm that goes beyond the abrogationof traditional cultural practices to seriousthreat to natural environmental structures. Thecultures of the different tribes in Nigerianeed to be revisited for evaluation and studiesto enable their integration into modernpractices that will make the environment moresustainable. This will be more productive thanthe unilateral introduction of programs,execution, and maintenance methods that arecompletely new, or in many cases run contraryto the cultural practices of the local peopleand tribes of Nigeria. (shrink)